Extracranial Meningioma-Pelvic Bone on FDG PET/CT: A Rare of the Rarest Site.

ABSTRACT: Meningiomas are benign extra-axial tumors of the central nervous system. Extracranial meningiomas are extremely rare (2%) and can develop as a direct extension from a primary intracranial meningioma or as a true primary extracranial meningioma originating from ectopic arachnoid cells. We report an extremely unusual case of a 61-year-old woman who was diagnosed with pelvic meningioma with the help of PET/CT and PET/CT-guided biopsy. The clinicopathological features of the patient and immunoprofile of the tumor are presented.

Interfollicular Hodgkin's lymphoma: A diagnostic challenge for pathologists.

Interfollicular Hodgkin's lymphoma (IFHL) is a rare pattern of classical Hodgkin's lymphoma (CHL) showing reactive follicular hyperplasia with involvement of the interfollicular area by HL. Two cases are reported in this study having primary IFHL out of total of 500 cases of CHL reported at our center. Diagnosis of IFHL was made on the basis of morphological and immunohistochemical features. As they represent an early stage of the disease, their identification and awareness s very important to get proper treatment at its earliest. This variant is very unusual and is diagnostically challenging for pathologists.

Synchronous uterine serous carcinoma and ovarian sex cord stromal tumor (thecoma)-A rare first case report.

Synchronous endometrial and ovarian carcinoma is a rare instance and it accounts for 50 to 70% of all synchronous female genital tract tumors. However, it is very rare to find synchronous endometrial carcinoma and ovarian sex cord-stromal tumor (thecoma). The present case is a 75-year-old woman with a complaint of post-menopausal vaginal bleeding. Radiologically, the magnetic resonance imaging (MRI) pelvis revealed altered signal intensity mass in the uterus. Frozen section and routine histopathological examination were done on radical hysterectomy. Microscopically, serous carcinoma involving uterine corpus and left Fallopian tube was identified along with the unusual finding of contralateral ovarian sex cord-stromal tumor (thecoma), which was confirmed on immunohistochemical examination. It is a very rare association and is first reported in the present study after a thorough search of the published literature. Their relationship based on a high level of estrogen produced by the hyperactive ovary is controversial as serous carcinomas are less hormone-dependent.

A Pilot Study on the Whole Exome Sequencing of Prostate Cancer in the Indian Phenotype Reveals Distinct Polymorphisms.

Prostate cancer (PCa) is the third most common cancer among men in India, and no next-generation sequencing (NGS) studies have been attempted earlier. Recent advances in NGS have heralded the discovery of biomarkers from Caucasian/European and Chinese ancestry, but not much is known about the Indian phenotype/variant of PCa. In a pilot study using the whole exome sequencing of benign/PCa patients, we identified characteristic mutations specific to the Indian sub-population. We observed a large number of mutations in DNA repair genes, viz. helicases, TP53, and BRCA besides the variants of unknown significance with a possibly damaging rare variant (rs730881069/chr19:55154172C/TR136Q) in the TNNI3 gene that has been previously reported as a semi-conservative amino acid substitution. Our pilot study attempts to bring an understanding of PCa prognosis and recurrence for the Indian phenotype.

Metastatic poorly differentiated prostatic carcinoma with neuroendocrine differentiation: negative on 68Ga-PSMA PET/CT.

Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68(HBED-CC)], abbreviated as Ga-PSMA, is a novel radiotracer undergoing evaluation for PET/CT imaging of prostate carcinoma. Its major advantage is the sensitive detection of lesions even at low prostate-specific antigen level and high target-to-background ratios obtained in metastatic lesions, which is better than that obtained with F-fluoromethylcholine. We present the case of a 28-year-old man with poorly differentiated prostate carcinoma with neuroendocrine differentiation, whose lesions did not show significant Ga-PSMA localization. As literature on utility of Ga-PSMA PET/CT for imaging prostate carcinoma grows, it is important to be aware of potential false negatives that could influence study results.

Multiple hepatic lesions in a case of isolated hepatic tuberculosis simulating metastases on 18F-FDG PET/CT imaging.

Hepatic tuberculosis is an unusual form of extrapulmonary tuberculosis and constitutes less than 1% of all cases of tuberculosis. Imaging studies for hepatic tuberculosis are nonspecific and mimic primary or metastatic carcinoma. Here we present ¹8F-FDG PET/CT images of a 25-year-old male patient with isolated hepatic tuberculosis.

Chronic intestinal pseudo-obstruction: systematic histopathological approach can clinch vital clues.

The histopathological approach of chronic intestinal pseudo-obstruction (CIP) is critical, and the findings are often missed by the histopathologists for lack of awareness and nonavailability of standard criteria. We aimed to describe a detailed histopathological approach for working-up cases of CIP by citing our experience. Eight suspected cases of CIP were included in the study to determine and describe an approach for reaching the histopathological diagnosis collected over a period of the last 1.5 years. The Hirschsprung's disease was put apart from the scope of this study. A detailed light microscopic analysis was performed along with special and immunohistochemical stains. Transmission electron microscopy was carried out on tissue retrieved from paraffin embedded tissue blocks. Among the eight cases, three were neonates, one in the pediatric age group, two adolescent, and two adults. After following the described critical approach, we achieved the histological diagnoses in all the cases. The causes of CIP noted were primary intestinal neuronal dysplasia (IND) type B (in 4), mesenchymopathy (in 2), lymphocytic myenteric ganglionitis (in 1), and duplication of myenteric plexus with leiomyopathy (in 1). Desmosis was noted in all of them along with other primary pathologies. One of the IND patients also had visceral myopathy, type IV. Histopathologists need to follow a systematic approach comprising of diligent histological examination and use of immunohistochemistry, immunocytochemistry, and electron microscopy in CIP workup. Therapy and prognosis vary depending on lesions identified by pathologists. These lesions can be seen in isolation or in combinations.

Asymptomatic solitary cerebral metastasis from papillary carcinoma thyroid: 131I SPECT/CT for accurate staging.

Isolated asymptomatic brain metastasis in papillary carcinoma thyroid (PCT) is extremely rare. We here present such a case of a 48-year-old woman with PCT. SPECT/CT localized the 131I radiotracer concentration seen on whole-body scan in this patient to the right posterior parietal cortex, suggesting brain metastasis. Contrast-enhanced MRI and 18F-FDG PET/CT confirmed the diagnosis and the patient was taken for gamma-knife radiosurgery. 131I SPECT/CT in this case accurately restaged the patient by detecting asymptomatic isolated brain metastasis and correctly directed the management strategy.

Calcifying epithelial odontogenic tumor (Pindborg tumor) without calcification: A rare entity.

The calcifying epithelial odontogenic tumor is a rare benign odontogenic tumor that was first described by Pindborg in 1955. It accounts for less than 1% of all odontogenic neoplasms. The tumor is characterized histologically by the presence of polygonal epithelial cells, calcification, and eosinophilic deposits resembling amyloid. Noncalcifying Pindborg tumor is very rare and only three cases have been documented in the English language literature so far. We present an additional case of noncalcifying Pindborg tumor and review the previously reported cases. Because noncalcifying Pindborg tumor is believed to be an aggressive variant, a definitive resection of the tumor with tumor-free surgical margins and long-term follow-up is recommended.